Watching Icelandic director Hlynur Palmason’s “A White, White Day” taught me an important lesson about the way suspense works in “slow cinema” — a term that describes deliberately paced, take-their-time narratives that aren’t necessarily preoccupied with action, quick cutting and the looming sense of imminent conflict. Just because a film forgoes these techniques doesn’t mean it’s not gripping, or engaging in its own way, although the tension works differently on our psyche. As it happens — and this is key — it wasn’t until a second viewing of “A White, White Day” that the revelation clicked. Let me explain.

Americans raised on a diet of Hollywood studio movies — which is the vast majority of them, myself included, since most of us eat what we’re served, and don’t always know where to find the alternative — are accustomed to intense, ticking-clock storytelling: movies in which our hero pursues a clear-cut goal with well-defined consequences within a narrow time frame. International directors, especially those who debut their work at film festivals, often reject this model. Instead, they might choose to frame scenes at a distance, focus on characters who aren’t inherently heroic and hold shots longer than seems natural, challenging audiences to adapt to their pacing.

That strategy can be taken to an extreme, but it can also be calibrated in such a way that it holds a patient, open-minded viewer in exquisite thrall. Consider the opening scene of “A White, White Day”: a long, unbroken shot of an SUV driving rapidly, even recklessly, along a slick, fogged-over highway. Visibility is poor. Audiences can make out no more than a single car-length in front of the driver, who weaves dangerously across the solid center line. Still, the camera maintains a steady distance at the same high speed, as the SUV brakes slightly around a dangerous curve more quickly than it should but continues on. And then something shocking but seemingly inevitable happens. The vehicle disappears from the frame, and the camera keeps rolling for a dozen more seconds.

This agonizing first scene runs for nearly two minutes. Just 98 seconds actually, but it feels like forever. How are our brains meant to process it? We never meet the character behind the wheel, never see her face. Our minds could be excused for drifting, and also for wanting something to occur. When it does, did we will the accident into happening? Is it our fault? As an audience watches a shot like this for the first time, an unexpected anxiety creeps in: We don’t know what we are waiting for, nor when or why the scene will end. Director Palmason sustains this nervous energy for the entire feature, such that every shot contains some degree of mystery as to its role in the story.

“A White, White Day” debuted in Critics’ Week at Cannes, where Ingvar Sigurdsson won the best actor prize, then traveled to the Karlovy Vary Film Festival, in what would prove to be a prestigious 11-month lead-in to its April 17 U.S. launch on the Film Movement streaming service. Seeing the film twice, at each of these two festivals, I discovered that the tension I’m describing exists only once: upon initial viewing. After that, the spell is broken. We read it differently. That’s also true of quick-cut Hollywood action movies, but it’s somehow more significant with slow cinema, because these films push back on formula and defy our expectations. We are learning how to watch them as they unfold.

Palmason ups the ante with the next scene, which is even more unconventional. Over the course of more than three minutes, he presents two dozen views of a rural Icelandic outpost, all captured from the exact same angle but at different hours of day, possibly even in different seasons. Later, we’ll learn that this building is one that Sigurdsson’s character, local police chief Ingimundur, is renovating for his daughter and her family. But for the time being, it is just an abstract structure, framed by mountains in the distance and wild horses in the foreground.

As demonstrated by his striking feature debut, 2017’s “Winter Brothers,” Palmason has a visual language and a relationship to time all his own. Separate from the film, he has devoted more than two years to a time-lapse photographic study documenting an equine corpse as it slowly decomposes — a project I see echoed in these shots of the house, which become a recurring motif, denoting the slow procession of days over the course of a film that assumes a kind of inexorable momentum as we find our bearings.

Eventually, “A White, White Day” snowballs into a muscular study of toxic masculinity set in one of the world’s more remote locations. That was Ingimundur’s wife at the wheel in the opening scene, her final moments. Two years later, he’s still processing her death, and discovering that perhaps their marriage wasn’t what it seemed. Nearly half an hour in — a long time to wait for such a development, although the movie is also about mourning the loss of a loved one, a process that refuses to follow a set schedule — he discovers a clue, tucked into a library book she’d borrowed, to a possible affair.

Any husband might be curious, but Ingimundur is a cop, and he starts to investigate. He calls, then later stalks the man he suspects of cuckolding him (Hilmir Snær Gudnason). All of a sudden, we seem to have arrived inside a more familiar movie: a story of jealousy and rage, about a grieving man desperate to regain some control over a tragedy he could not prevent, pushed to potentially violent extremes. Sigurdsson, who sometimes appears in small roles in Hollywood blockbusters, delivers an astonishing performance here, a display of locomotive determination and exasperated futility transformed into dangerous, unpredictable anger.

That primitive, almost instinctual energy is offset by a much younger actor, Ida Mekkin Hlynsdottir, who plays his 8-year-old granddaughter, Salka, the lone character with whom Ingimundur reveals his tender side (contrast this with a therapy session, in which he destroys the computer on which his psychologist appears via Skype, and we see the full, frightening range of his emotional capacity). In the old man’s head, we suspect he is doing this for her, trying to rectify an unfair world for Salka’s benefit. But in fact, he is becoming monstrous before her eyes.

Crucial to what makes “A White, White Day” such a terrifying, soul-rattling character study is the way Palmason subverts and reinvents so much of might sound generic about this transformation. The underlying psychology might seem familiar, but it is parceled out in surprising ways, in scenes observed from unexpected angles in the director’s carefully manipulated sense of real time. Now that the film is available for streaming, I wonder how well this near-hypnotic control Palmason achieves can translate to the small screen. In light of my own experience with the film, I recommend the following. See it twice: a virgin viewing, simply to take in the strange counterintuitive way the story unfolds, and then again, with a bit of distance, knowing where the journey is headed, so that you might fully appreciate the genius of its construction. I’m convinced that “A White, White Day” is the work of one of the most important voices of this emerging generation, arriving at a stage where we have yet to learn his language.